[FrameworkBundle] KernelTestCase Resetting Services take more memory than without

[alexander-schranz]

Symfony version(s) affected

6.3.1 (not sure if lowers also effected)

Description

I'm currently fighting memory issues in a projects tests. I stumble over #45668 and in my case reverting that change uses less memory than more memory e.g.:

Before (with $container->reset()) memory increases faster:

After (without $container->reset()) memory increases not so fast:

How to reproduce

I'm not able to share the project. But the Extension outputting the memory usage from class to class can be found here: https://gist.github.com/alexander-schranz/d2b30177c1043099c44ef50b33db8412

So maybe somebody can test its own project if it increases or decreases when not call $container->reset() method.

Possible Solution

     protected static function ensureKernelShutdown()
     {

         if (null !== static::$kernel) {
             static::$kernel->boot();
-            $container = static::$kernel->getContainer();
             static::$kernel->shutdown();
             static::$booted = false;
             static::$kernel = null;

-            if ($container instanceof ResetInterface) {
-                $container->reset();
-            }
         }
     }

Additional Context

No response

[nicolas-grekas]

gc_collect_cycles to the rescue?

[alexander-schranz]

Sadly not actually, no changes measured on using gc_collect_cycles. Tried unsetting all my own test properties and calling gc_collect_cycles after every test: https://gist.github.com/alexander-schranz/f0e0bfd8c862b08373a97ff0ceed5192#file-cleanuppropertiestestlistener-php-L32. But that didn't decrease any memory usage for this test suite.

[alexander-schranz]

Got time today to run the whole test suite, the endresult of the whole test suite is not so dramatic as the first few tests but still it improves and currently avoids that our CI running into Killed by no memory available:

With Reset:

Memory: 2.21 GB

Without Reset (currently vendor-patched the class):

Memory: 1.98 GB

@nicolas-grekas are always all services reseted? Or only the one which where used?

[carsonbot]

Hey, thanks for your report!
There has not been a lot of activity here for a while. Is this bug still relevant? Have you managed to find a workaround?

[alexander-schranz]

I still use the vendor patch in the project to avoid memory increasing unexpectly.